* {
    margin: 0;
    padding: 0;
}

header {
    height: 60px;
    background-color: pink;
}

aside {
    height: calc(100vh - 60px);
    width: 100px;
    background-color: green;
    display: flex;
    flex-direction: column;
}

section {
    display: flex;
}

main {
    flex-grow: 1;
    display: flex;
    align-items: center;
    justify-content: center;
}